This project seeks to (1) characterize processes by which organisms maintain memories in a transient active state and (2) then determine the relationship between such short-term memory processes and those post-trial processes presumed responsible for acquisition of more durable associations in long-term memory. During this project period, research will focus on three areas. First, it is known that changes in delay-interval stimuli disrupt delayed matching performances in a number of different species, but work in this laboratory has shown that extended training produces "recovery from retroactive interference." Possible mechanisms underlying that recovery will be investigated using various transfer of training designs. Second, brief stimuli that occur during the delay and that signal omission of end-of-trial reinforcement appear to result in loss of short-term memory ("directed forgetting"). The transferability of cuing effects among different tasks will be explored and observational work will determine whether the effects are merely due to peripheral mediating behaviors. Third, methods for studying avian spatial memory will be developed with the objective of determining the comparative generality of some striking features of mammalian spatial memory (e.g., its longevity and resistance to retroactive interference).